Manufacture of concentrated nitric acid



25 o tion of'the nitric anhydrid, 1n the presence UMTED STATES PATENT o F FICE.

' I PEILIPPE ntrous'rn em or GENEVA, swrrznnnm, 'Assmnon. 'ro mnrnmn l ones a BOUGHARDY, or rams, FRANGE,'A FIRM.

facture of Concentrated Nitric Acid, of

- which the following isa specification.

There are a number of patents for the manufactufe of concentrated nitric acid startinggwith-NO, and water or dilute nitric" aeid. y the reaction of the N0 vapors with water an acid of only about 60%, strength obtained; by using liquid N 2 concentrations ofabout 90% are obtained. These do not produce 100% nitric acid.

for the manufacture of very highly concen trated nitric acid by causing the reaction of oxid of nitro 'en and-ozone. The nitrogen,"-

nitric acid, of a concentration such as is obtained. by means of the processes above referred to-or of any other desired or avail-.

able concentratiom'with nitric anhydrid. In

view of the extremely rapid decomposition of the N 0 the reaction is advantageously efiecte'd at the very moment of the formaof the solution, by the reaction between perperoxid may" "introduced any physlcal orm, but to facilitate the control, preferably in the form :of vapor:- 'lhe -ozone may be used in'a1 1y,f ,or1'n.- The -ozone'and the NO, may be .fedin anydesired proportions, but losseswilloocur if either reagent be excew of the, other, -ai1d eonsequentlystheoat I PIHLIPPE .AUGUSTE Gm, a citizeno'f the wiss Republic, residing in Geneva,'Switzerland, have inventeda certain new and useful Improved Manu- Specification of Letters Patent. P t nt 0, 1920. Application filed Hay), 1918. ser al mfa'aa'sev.

ozonized oxygen or air and nitrogen peroxid. Gaseous nitric anhydrid (N 0,) is' fqrmed and this reacts at once with the water'of the solution'of nitric acid yielding more n tric acid; the operation is continued until the liquidhas attained the desired "de- 7 gree of concentration. 7

Havingthus described the nature of the] said invention and the best means I know of carry g the same into practical eflect; I-' claim;--, t V- 1 A process for the manufacture of con-. eentrated nitric acidiby causing-an aqueous A ,solution of-nitric acid to react with nitric The present invention relates to a process ablelstrength is passed a gaseouscurrent of anhydrid'at vthe moment of its formation,

formed'in immediate proximity to ,the solution by .theereaction between mtric peroxid .and ozone; j:

2. The processof manufacturing nitric peroxid with ozone. r

, The processofmanufact 't-rated'nitric acidwhich consists ln treating 'nitro'genj'peroxid with" ozone in the presence uringeoncen 65 of. a'f more dilute aqueous solution of nitric a flm .a e. o is i nii the WWW of I retical proportions-result in economy? .v I two; subscribing witnesses.- y

T ai l wine'i an m q f tab k PHILIPPE XI'J'GU's'TEGUiE;

' 'Into the aqneous-nitrici-acidwh ch fisj-to Witnesses I ,4: ofmanufacturing conceiitratednitric acid which consists in treat-' nitrogenperoxid with ozone to form 

